[deliverable/linux.git] / fs / fat / misc.c

/*
 *  linux/fs/fat/misc.c
 *
 *  Written 1992,1993 by Werner Almesberger
 *  22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
 *		 and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/time.h>
#include "fat.h"

/*
 * fat_fs_error reports a file system problem that might indicate fa data
 * corruption/inconsistency. Depending on 'errors' mount option the
 * panic() is called, or error message is printed FAT and nothing is done,
 * or filesystem is remounted read-only (default behavior).
 * In case the file system is remounted read-only, it can be made writable
 * again by remounting it.
 */
void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
{
	struct fat_mount_options *opts = &MSDOS_SB(sb)->options;
	va_list args;
	struct va_format vaf;

	if (report) {
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		fat_msg(sb, KERN_ERR, "error, %pV", &vaf);
		va_end(args);
	}

	if (opts->errors == FAT_ERRORS_PANIC)
		panic("FAT-fs (%s): fs panic from previous error\n", sb->s_id);
	else if (opts->errors == FAT_ERRORS_RO && !(sb->s_flags & MS_RDONLY)) {
		sb->s_flags |= MS_RDONLY;
		fat_msg(sb, KERN_ERR, "Filesystem has been set read-only");
	}
}
EXPORT_SYMBOL_GPL(__fat_fs_error);

/**
 * fat_msg() - print preformated FAT specific messages. Every thing what is
 * not fat_fs_error() should be fat_msg().
 */
void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	printk("%sFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
	va_end(args);
}

/* Flushes the number of free clusters on FAT32 */
/* XXX: Need to write one per FSINFO block.  Currently only writes 1 */
int fat_clusters_flush(struct super_block *sb)
{
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	struct buffer_head *bh;
	struct fat_boot_fsinfo *fsinfo;

	if (sbi->fat_bits != 32)
		return 0;

	bh = sb_bread(sb, sbi->fsinfo_sector);
	if (bh == NULL) {
		fat_msg(sb, KERN_ERR, "bread failed in fat_clusters_flush");
		return -EIO;
	}

	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
	/* Sanity check */
	if (!IS_FSINFO(fsinfo)) {
		fat_msg(sb, KERN_ERR, "Invalid FSINFO signature: "
		       "0x%08x, 0x%08x (sector = %lu)",
		       le32_to_cpu(fsinfo->signature1),
		       le32_to_cpu(fsinfo->signature2),
		       sbi->fsinfo_sector);
	} else {
		if (sbi->free_clusters != -1)
			fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
		if (sbi->prev_free != -1)
			fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
		mark_buffer_dirty(bh);
	}
	brelse(bh);

	return 0;
}

/*
 * fat_chain_add() adds a new cluster to the chain of clusters represented
 * by inode.
 */
int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
{
	struct super_block *sb = inode->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	int ret, new_fclus, last;

	/*
	 * We must locate the last cluster of the file to add this new
	 * one (new_dclus) to the end of the link list (the FAT).
	 */
	last = new_fclus = 0;
	if (MSDOS_I(inode)->i_start) {
		int fclus, dclus;

		ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
		if (ret < 0)
			return ret;
		new_fclus = fclus + 1;
		last = dclus;
	}

	/* add new one to the last of the cluster chain */
	if (last) {
		struct fat_entry fatent;

		fatent_init(&fatent);
		ret = fat_ent_read(inode, &fatent, last);
		if (ret >= 0) {
			int wait = inode_needs_sync(inode);
			ret = fat_ent_write(inode, &fatent, new_dclus, wait);
			fatent_brelse(&fatent);
		}
		if (ret < 0)
			return ret;
		/*
		 * FIXME:Although we can add this cache, fat_cache_add() is
		 * assuming to be called after linear search with fat_cache_id.
		 */
//		fat_cache_add(inode, new_fclus, new_dclus);
	} else {
		MSDOS_I(inode)->i_start = new_dclus;
		MSDOS_I(inode)->i_logstart = new_dclus;
		/*
		 * Since generic_write_sync() synchronizes regular files later,
		 * we sync here only directories.
		 */
		if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
			ret = fat_sync_inode(inode);
			if (ret)
				return ret;
		} else
			mark_inode_dirty(inode);
	}
	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
		fat_fs_error(sb, "clusters badly computed (%d != %llu)",
			     new_fclus,
			     (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
		fat_cache_inval_inode(inode);
	}
	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);

	return 0;
}

/*
 * The epoch of FAT timestamp is 1980.
 *     :  bits :     value
 * date:  0 -  4: day	(1 -  31)
 * date:  5 -  8: month	(1 -  12)
 * date:  9 - 15: year	(0 - 127) from 1980
 * time:  0 -  4: sec	(0 -  29) 2sec counts
 * time:  5 - 10: min	(0 -  59)
 * time: 11 - 15: hour	(0 -  23)
 */
#define SECS_PER_MIN	60
#define SECS_PER_HOUR	(60 * 60)
#define SECS_PER_DAY	(SECS_PER_HOUR * 24)
/* days between 1.1.70 and 1.1.80 (2 leap days) */
#define DAYS_DELTA	(365 * 10 + 2)
/* 120 (2100 - 1980) isn't leap year */
#define YEAR_2100	120
#define IS_LEAP_YEAR(y)	(!((y) & 3) && (y) != YEAR_2100)

/* Linear day numbers of the respective 1sts in non-leap years. */
static time_t days_in_year[] = {
	/* Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec */
	0,   0,  31,  59,  90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
};

/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
		       __le16 __time, __le16 __date, u8 time_cs)
{
	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
	time_t second, day, leap_day, month, year;

	year  = date >> 9;
	month = max(1, (date >> 5) & 0xf);
	day   = max(1, date & 0x1f) - 1;

	leap_day = (year + 3) / 4;
	if (year > YEAR_2100)		/* 2100 isn't leap year */
		leap_day--;
	if (IS_LEAP_YEAR(year) && month > 2)
		leap_day++;

	second =  (time & 0x1f) << 1;
	second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
	second += (time >> 11) * SECS_PER_HOUR;
	second += (year * 365 + leap_day
		   + days_in_year[month] + day
		   + DAYS_DELTA) * SECS_PER_DAY;

	if (!sbi->options.tz_set)
		second += sys_tz.tz_minuteswest * SECS_PER_MIN;
	else
		second -= sbi->options.time_offset * SECS_PER_MIN;

	if (time_cs) {
		ts->tv_sec = second + (time_cs / 100);
		ts->tv_nsec = (time_cs % 100) * 10000000;
	} else {
		ts->tv_sec = second;
		ts->tv_nsec = 0;
	}
}

/* Convert linear UNIX date to a FAT time/date pair. */
void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
		       __le16 *time, __le16 *date, u8 *time_cs)
{
	struct tm tm;
	time_to_tm(ts->tv_sec,
		   (sbi->options.tz_set ? sbi->options.time_offset :
		   -sys_tz.tz_minuteswest) * SECS_PER_MIN, &tm);

	/*  FAT can only support year between 1980 to 2107 */
	if (tm.tm_year < 1980 - 1900) {
		*time = 0;
		*date = cpu_to_le16((0 << 9) | (1 << 5) | 1);
		if (time_cs)
			*time_cs = 0;
		return;
	}
	if (tm.tm_year > 2107 - 1900) {
		*time = cpu_to_le16((23 << 11) | (59 << 5) | 29);
		*date = cpu_to_le16((127 << 9) | (12 << 5) | 31);
		if (time_cs)
			*time_cs = 199;
		return;
	}

	/* from 1900 -> from 1980 */
	tm.tm_year -= 80;
	/* 0~11 -> 1~12 */
	tm.tm_mon++;
	/* 0~59 -> 0~29(2sec counts) */
	tm.tm_sec >>= 1;

	*time = cpu_to_le16(tm.tm_hour << 11 | tm.tm_min << 5 | tm.tm_sec);
	*date = cpu_to_le16(tm.tm_year << 9 | tm.tm_mon << 5 | tm.tm_mday);
	if (time_cs)
		*time_cs = (ts->tv_sec & 1) * 100 + ts->tv_nsec / 10000000;
}
EXPORT_SYMBOL_GPL(fat_time_unix2fat);

int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
{
	int i, err = 0;

	for (i = 0; i < nr_bhs; i++)
		write_dirty_buffer(bhs[i], WRITE);

	for (i = 0; i < nr_bhs; i++) {
		wait_on_buffer(bhs[i]);
		if (!err && !buffer_uptodate(bhs[i]))
			err = -EIO;
	}
	return err;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/fat/misc.c
	3	*
	4	* Written 1992,1993 by Werner Almesberger
	5	* 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
	6	* and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/fs.h>
1da177e4	11	#include <linux/buffer_head.h>
1d81a181	12	#include <linux/time.h>
9e975dae	13	#include "fat.h"
1da177e4 LT	14
1da177e4 LT	15	/*
85c78591 DK	16	* fat_fs_error reports a file system problem that might indicate fa data
	17	* corruption/inconsistency. Depending on 'errors' mount option the
	18	* panic() is called, or error message is printed FAT and nothing is done,
	19	* or filesystem is remounted read-only (default behavior).
	20	* In case the file system is remounted read-only, it can be made writable
	21	* again by remounting it.
1da177e4	22	*/
2c8a5ffb	23	void __fat_fs_error(struct super_block sb, int report, const char fmt, ...)
1da177e4	24	{
2c8a5ffb	25	struct fat_mount_options *opts = &MSDOS_SB(sb)->options;
1da177e4	26	va_list args;
2c8a5ffb	27	struct va_format vaf;
1da177e4	28
aaa04b48	29	if (report) {
aaa04b48	30	va_start(args, fmt);
2c8a5ffb AF	31	vaf.fmt = fmt;
2c8a5ffb AF	32	vaf.va = &args;
e68e96d2	33	fat_msg(sb, KERN_ERR, "error, %pV", &vaf);
aaa04b48	34	va_end(args);
aaa04b48	35	}
1da177e4	36
85c78591	37	if (opts->errors == FAT_ERRORS_PANIC)
2c8a5ffb AF	38	panic("FAT-fs (%s): fs panic from previous error\n", sb->s_id);
	39	else if (opts->errors == FAT_ERRORS_RO && !(sb->s_flags & MS_RDONLY)) {
	40	sb->s_flags \|= MS_RDONLY;
e68e96d2	41	fat_msg(sb, KERN_ERR, "Filesystem has been set read-only");
1da177e4 LT	42	}
1da177e4 LT	43	}
aaa04b48	44	EXPORT_SYMBOL_GPL(__fat_fs_error);
1da177e4	45
81ac21d3 AF	46	/**
	47	* fat_msg() - print preformated FAT specific messages. Every thing what is
	48	* not fat_fs_error() should be fat_msg().
	49	*/
	50	void fat_msg(struct super_block sb, const char level, const char *fmt, ...)
	51	{
	52	struct va_format vaf;
	53	va_list args;
	54
	55	va_start(args, fmt);
	56	vaf.fmt = fmt;
	57	vaf.va = &args;
	58	printk("%sFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
	59	va_end(args);
	60	}
	61
1da177e4 LT	62	/* Flushes the number of free clusters on FAT32 */
1da177e4 LT	63	/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
ed248b29	64	int fat_clusters_flush(struct super_block *sb)
1da177e4 LT	65	{
	66	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	67	struct buffer_head *bh;
	68	struct fat_boot_fsinfo *fsinfo;
	69
	70	if (sbi->fat_bits != 32)
ed248b29	71	return 0;
1da177e4 LT	72
	73	bh = sb_bread(sb, sbi->fsinfo_sector);
	74	if (bh == NULL) {
869f58c0	75	fat_msg(sb, KERN_ERR, "bread failed in fat_clusters_flush");
ed248b29	76	return -EIO;
1da177e4 LT	77	}
	78
	79	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
	80	/* Sanity check */
	81	if (!IS_FSINFO(fsinfo)) {
869f58c0 AF	82	fat_msg(sb, KERN_ERR, "Invalid FSINFO signature: "
869f58c0 AF	83	"0x%08x, 0x%08x (sector = %lu)",
1da177e4 LT	84	le32_to_cpu(fsinfo->signature1),
	85	le32_to_cpu(fsinfo->signature2),
	86	sbi->fsinfo_sector);
	87	} else {
	88	if (sbi->free_clusters != -1)
	89	fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
	90	if (sbi->prev_free != -1)
	91	fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
	92	mark_buffer_dirty(bh);
1da177e4 LT	93	}
1da177e4 LT	94	brelse(bh);
ed248b29 OH	95
ed248b29 OH	96	return 0;
1da177e4 LT	97	}
	98
	99	/*
	100	* fat_chain_add() adds a new cluster to the chain of clusters represented
	101	* by inode.
	102	*/
	103	int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
	104	{
	105	struct super_block *sb = inode->i_sb;
	106	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	107	int ret, new_fclus, last;
	108
	109	/*
	110	* We must locate the last cluster of the file to add this new
	111	* one (new_dclus) to the end of the link list (the FAT).
	112	*/
	113	last = new_fclus = 0;
	114	if (MSDOS_I(inode)->i_start) {
	115	int fclus, dclus;
	116
	117	ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
	118	if (ret < 0)
	119	return ret;
	120	new_fclus = fclus + 1;
	121	last = dclus;
	122	}
	123
	124	/* add new one to the last of the cluster chain */
	125	if (last) {
	126	struct fat_entry fatent;
	127
	128	fatent_init(&fatent);
	129	ret = fat_ent_read(inode, &fatent, last);
	130	if (ret >= 0) {
	131	int wait = inode_needs_sync(inode);
	132	ret = fat_ent_write(inode, &fatent, new_dclus, wait);
	133	fatent_brelse(&fatent);
	134	}
	135	if (ret < 0)
	136	return ret;
c39540c6 R	137	/*
	138	* FIXME:Although we can add this cache, fat_cache_add() is
	139	* assuming to be called after linear search with fat_cache_id.
	140	*/
1da177e4 LT	141	// fat_cache_add(inode, new_fclus, new_dclus);
	142	} else {
	143	MSDOS_I(inode)->i_start = new_dclus;
	144	MSDOS_I(inode)->i_logstart = new_dclus;
	145	/*
2f3d675b JK	146	* Since generic_write_sync() synchronizes regular files later,
2f3d675b JK	147	* we sync here only directories.
1da177e4 LT	148	*/
	149	if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
	150	ret = fat_sync_inode(inode);
	151	if (ret)
	152	return ret;
	153	} else
	154	mark_inode_dirty(inode);
	155	}
	156	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
85c78591	157	fat_fs_error(sb, "clusters badly computed (%d != %llu)",
c3302931 OH	158	new_fclus,
c3302931 OH	159	(llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
1da177e4 LT	160	fat_cache_inval_inode(inode);
	161	}
	162	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
	163
	164	return 0;
	165	}
	166
7decd1cb OH	167	/*
	168	* The epoch of FAT timestamp is 1980.
	169	* : bits : value
	170	* date: 0 - 4: day (1 - 31)
	171	* date: 5 - 8: month (1 - 12)
	172	* date: 9 - 15: year (0 - 127) from 1980
	173	* time: 0 - 4: sec (0 - 29) 2sec counts
	174	* time: 5 - 10: min (0 - 59)
	175	* time: 11 - 15: hour (0 - 23)
	176	*/
	177	#define SECS_PER_MIN 60
	178	#define SECS_PER_HOUR (60 * 60)
	179	#define SECS_PER_DAY (SECS_PER_HOUR * 24)
7decd1cb OH	180	/* days between 1.1.70 and 1.1.80 (2 leap days) */
	181	#define DAYS_DELTA (365 * 10 + 2)
	182	/* 120 (2100 - 1980) isn't leap year */
	183	#define YEAR_2100 120
	184	#define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)
	185
1da177e4	186	/* Linear day numbers of the respective 1sts in non-leap years. */
7decd1cb OH	187	static time_t days_in_year[] = {
	188	/* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
	189	0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
1da177e4 LT	190	};
1da177e4 LT	191
7decd1cb OH	192	/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
	193	void fat_time_fat2unix(struct msdos_sb_info sbi, struct timespec ts,
	194	__le16 __time, __le16 __date, u8 time_cs)
1da177e4	195	{
7decd1cb OH	196	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
7decd1cb OH	197	time_t second, day, leap_day, month, year;
1da177e4	198
7decd1cb OH	199	year = date >> 9;
	200	month = max(1, (date >> 5) & 0xf);
	201	day = max(1, date & 0x1f) - 1;
	202
	203	leap_day = (year + 3) / 4;
	204	if (year > YEAR_2100) /* 2100 isn't leap year */
	205	leap_day--;
	206	if (IS_LEAP_YEAR(year) && month > 2)
	207	leap_day++;
	208
	209	second = (time & 0x1f) << 1;
	210	second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
	211	second += (time >> 11) * SECS_PER_HOUR;
	212	second += (year * 365 + leap_day
	213	+ days_in_year[month] + day
	214	+ DAYS_DELTA) * SECS_PER_DAY;
	215
58156c8f	216	if (!sbi->options.tz_set)
7decd1cb	217	second += sys_tz.tz_minuteswest * SECS_PER_MIN;
58156c8f JK	218	else
58156c8f JK	219	second -= sbi->options.time_offset * SECS_PER_MIN;
7decd1cb OH	220
	221	if (time_cs) {
	222	ts->tv_sec = second + (time_cs / 100);
	223	ts->tv_nsec = (time_cs % 100) * 10000000;
	224	} else {
	225	ts->tv_sec = second;
	226	ts->tv_nsec = 0;
	227	}
1da177e4 LT	228	}
1da177e4 LT	229
7decd1cb OH	230	/* Convert linear UNIX date to a FAT time/date pair. */
	231	void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec ts,
	232	__le16 time, __le16 date, u8 *time_cs)
1da177e4	233	{
1d81a181	234	struct tm tm;
58156c8f JK	235	time_to_tm(ts->tv_sec,
	236	(sbi->options.tz_set ? sbi->options.time_offset :
	237	-sys_tz.tz_minuteswest) * SECS_PER_MIN, &tm);
1da177e4	238
1d81a181 Z	239	/* FAT can only support year between 1980 to 2107 */
1d81a181 Z	240	if (tm.tm_year < 1980 - 1900) {
7decd1cb OH	241	*time = 0;
	242	*date = cpu_to_le16((0 << 9) \| (1 << 5) \| 1);
	243	if (time_cs)
	244	*time_cs = 0;
	245	return;
	246	}
1d81a181	247	if (tm.tm_year > 2107 - 1900) {
7decd1cb OH	248	*time = cpu_to_le16((23 << 11) \| (59 << 5) \| 29);
	249	*date = cpu_to_le16((127 << 9) \| (12 << 5) \| 31);
	250	if (time_cs)
	251	*time_cs = 199;
	252	return;
	253	}
7decd1cb	254
1d81a181 Z	255	/* from 1900 -> from 1980 */
	256	tm.tm_year -= 80;
	257	/* 0~11 -> 1~12 */
	258	tm.tm_mon++;
	259	/* 0~59 -> 0~29(2sec counts) */
	260	tm.tm_sec >>= 1;
1da177e4	261
1d81a181 Z	262	*time = cpu_to_le16(tm.tm_hour << 11 \| tm.tm_min << 5 \| tm.tm_sec);
1d81a181 Z	263	*date = cpu_to_le16(tm.tm_year << 9 \| tm.tm_mon << 5 \| tm.tm_mday);
7decd1cb OH	264	if (time_cs)
	265	time_cs = (ts->tv_sec & 1) 100 + ts->tv_nsec / 10000000;
	266	}
	267	EXPORT_SYMBOL_GPL(fat_time_unix2fat);
1da177e4 LT	268
	269	int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
	270	{
5b00226d	271	int i, err = 0;
1da177e4	272
9cb569d6 CH	273	for (i = 0; i < nr_bhs; i++)
	274	write_dirty_buffer(bhs[i], WRITE);
	275
1da177e4 LT	276	for (i = 0; i < nr_bhs; i++) {
1da177e4 LT	277	wait_on_buffer(bhs[i]);
0edd55fa	278	if (!err && !buffer_uptodate(bhs[i]))
1da177e4 LT	279	err = -EIO;
	280	}
	281	return err;
	282	}